Hormones Flashcards
Different Types of Hormones
Steroids Lipids Proteins Peptides Amino Acid Derivatives Hormone Like: gases- give like hormone response; environment changes
Receptors
Proteins: transmembrane/plasma membrane
Selectivity of Hormone Response
Not all cells respond to hormone
Response is dependent oh hormone present, receptor present and Hormone Receptor affinity and Receptor binding to cell components
Locations of Hormones
Endocrine glands: exit gland and go into the receptor
Can come from cells that are neighbors (paracrine)
Cells can make their own hormone and respond to it (autocrine)
Why we have hormones?
Regulate physiology
Regulating homeostasis: steady state condition
Process is dynamic and responds to stimuli
Negative Feedback (Provide Example)
Keeps things constant
Change in variable causes the reverse of the change
Example: Cortisol sends a signal to the hypothalamus to turn down the production of (corticotropin releasing factor) CRF and (adrencorticotrophic) ACTH
Positive Feedback (Provide Example)
Change amplifies the change
Example: Labor; pressure of the baby’s hear causes contractions and the contractions cause more pressure (production oxytocin)
Heartbeat Hormone
Tyrosine converts epinephrine
Epinephrine causes the heart to beat faster as well as gives you an alertness
Hormone Agonist
Hormone binds to the receptor and get a response
Hormone Antagonist
Hormone binds to the receptor but get no response
Hormone agonist in presence of antagonist gets no response
Homeostasis
Steady state or internal balance
Maintain constant internal systems even when external environment undergoes a change
Glucose Homeostasis
Regulated by two distinct classes of cell surface receptors (Insulin Receptor and Glucagon Receptor) that function through different signal transduction pathways
Insulin Receptor
Receptor Tyrosine Kinase and binding of signaling molecules to phosphorylated receptor IRS1
Glucagon Receptor
GDP/GTP exchange on G protein, activation of adenylate cyclase and increase in cAMP levels
Androgen Insensitivity Syndrome (AIS)
Mutations in the androgen receptor (AR) promoter or in specific functional domains of the receptor protein
in human males, the fetus must respond to testosterone(androgen) to look male on the outside
when a mutation in the AR prevents expression or function the XY individual can not properly respond to testosterone and looks female outside (male inside)
Hormone Sequence of Events
Inactive Receptor
Hormone Binds
Receptor Dimerizes
Activate Enzyme in Receptor itself
Phosphoralation of the other receptors’ sub unit
Cell signaling molecules bind and kick on a lot of other reactions
Type 1 Diabetes
Beta Islet destruction; loss of insulin production
Type 2 Diabetes
Insulin deficiencies; receptor mutations
defects in cell signaling molecules
Glucagon Receptor
Set of receptors that pass through the membrane 7 times (7 pass transmembrane receptor)
G protein binds to guanine nucleotides
Adenylate cyclase turns ATP into cAMP
cAMP converts glycogen into glucose
